Automatic telephone signal-transmitting method and device



\ Dec. 20, 1932. c. s. BATDORF AUTOMATIC TELEPHONE SIGNAL TRANSMITTING METHOD AND DEVICE Filed Feb. 1, 1932 5 Sheets Sheet 1 M III. 1234567 890 E 7 9 m N FILOSVY mm W MEHTNRU w ADG. MPTW CFIL TQV .2 BEHK .RU P Z DG PTW INVENTOR 6' 66/7156 5'. fiaraaxr;

ATTORNEY 0987654321 SOL F a)! W RNKHEB 0| WTPMJGDA 3 RY SOL a U hX NKH WTPMJG A 'lllll Dec. 20, 1932. c s, BATDORF 1,891,633

AUTOMATIC TELEPHONE SIGNAL TRANSMITTING METHOD AMDDEVICE Filed Feb. 1, 1952 5 Sheets-Sheet 2 'INVENTOR 54 4/3455 5. Berna/PF ATTORNEY Dec. 20, 1932.

c. s. BATDORF 1,891,633 AUTOMATIC TELEPHONE SIGNAL TRANSMITTING METHOD AND DEVICE Filed Feb. 1, 1952 v 5 Sheets-Shet a I h I INVENTQR 61 9915; 5. 507000- WM P- ATTORNEY Dec 20, 1932. c. s. BATDORF AUTOMATIC TELEPHONE SIGNAL TRANSMITTING METHOD AND DEVICE Filed Feb. 1, 1932 5 Sheets-Sheet 4 ATTORNEY Dec. 20, 1932. c. s. BATDORF 1,391,633

AUTOMATIC TELEPHONE SIGNAL TRANSMITTING METHOD AND DEVICE Filed Feb. 1, 1932 5 Sheets-Sheet 5 /5. 5/, az, as .34 .53; 5i 3/; 40 I l 7 l INVENTOR w flr'ifizss 5'. 547-009,:

Patented Dec. 20, 1932 UNITED, STATES CHARLES S. IBATDORF, E BROOKLYN, NEW YORK AUTOMATIC TELEPHONE SIGNAL-TRANSMITTING IYIIETHOD AND DEVICE Application filed February 1, 1932. Serial No. 589.998.

This invention relates to signal-transmitting methods and devices for use in connection with automatic telephone systems, and particularly to methods of transmitting signals, and transmitters, of the character used in automatic telephone systems wherein the selective switches for establishing connections are operated in response to current impulses induced by such transmitters. Such signals correspond with the so-called telephone numbers and consist normally of seven elements, each com rising a number of impulses determined y the individual digits of the number.

nals automatically, and with the elimination of the manual selection of the elements of the signal to be transmitted, or of the danger of incorrect manual selection, and of human interference with the correct transmission of the signal selected.

It is a primary object of my invention toprovide a mechanical signal transmitting device by means of which a predetermined signal may be selected and transmitted automatically, without requiring human selection of the signal elements to be transmitted, or even knowledge of the number called.

It is an object of my invention to provide a signal-transmitting device by means of which the person making the call can set up the number to be called and verify the same before the receiver is removed from the hook and the signal transmitted.

Another object of my invention is to provide a signal-transmitting device by means of which, after the number has been set up and verified by the person making the call,

the actual transmission of the signal is automatic and beyond the control of the person making the call.

With these objects in view, and suchother objects as will appear from this specification,

my invention consists in the methods, con- My invention has for its object a novel method of transmitting such telephone sig-' structions, combinations and arrangements of parts herein described and claimed, and shown in the accompanying drawings.

In these drawings, which show a. preferred embodiment of my invention, and are illustrative of one way of putting my method into practice:

Figure l'is a side elevation of my signaltransmitting device showing its attachment to the base plate of an ordinary telephone instrument;

Fig. 2 is a in Fig. 1;

Fig. 3 is a plan View of the selective contact plates in the positions in which they appear in Fig. 2, with the top of the casing removed;

Fig. 4 is a transverse vertical section, taken approximately on the line 4-4 of Fig. 6 looking in the direction of the arrows;

Fig. 5 is a view looking from beneath up- Ward at the contact plates shown in Fig. 3;

Fig. 6 is a longitudinal; vertical section, taken approximately on the longitudinal centre line of the device;

Fig. '7 is a section through the operatin 7 knob, taken approximately on the line 7- of Fig. .6, looking in the direction of the arrows;

Fig. 8 is a detail section taken ap roximately on the line 88 of Fig. 6 looking in 7 the direction of the arrows;

Fig. 9 is a sectional view taken a proximately on the line 9-9 of Fig. 6 100 'ng in the direction of the arrows, showing the parts in normal position;

Fig. 10 is a sectional view corresponding 1 with Fig. 9, but showing the operating parts in position to commence the automatic transmission of the signal;

Fig. 11 is a plan view of an automatic selector plate for the automatic selection of a predetermined signal;

Fig. 12 is a section through such a selector plate, taken approximately on the line 12-12 of Fig. 11;

plan view of the device shown cept those to which access is necessary for the selection or setting up of the signal to be transmitted, and for the setting of the apparatus to eifect the automatic transmission of the signal. The base plate 21 is capable of being connected with the telephone instru ment in substantially the same manner as the dial transmitters now in general use. Immediately under the top face of the casing 20 are located a plurality of contact plates, 31, 32, 33, 34, 35, 36, 37, one for each element of the signals to be transmitted. These contact plates are slidably mounted upon a plate 40, and each is provided with a lug or actuating portion 30 which projects upward through one of a number of corresponding slots 22 formed in the casing 20. Alongside each of the slots 22 are provided letters or numbers corresponding with the several operative positions of each of the slidable contact plates 31-37 inclusive. Thus the selection of the positions, or placing, of the contact plates 31-37 for the transmission of a predetermined signal is effected by setting the respective lugs 30 in their slots 22 opposite the numbers corresponding to the particular digits or elements of the predetermined signal.

It will be noted that the contact plates 31-37 themselves, as shown in Fig. 3, each have a series of letters or numbers upon their upper surfaces corresponding with the letters or numbers on the casing, the series on the contact plates running in the reverse direction. These numbers are useful in connection with openings 23 arranged in a line across the'top face of the casing 20, so that when the lugs 30 have been set opposite the numbers on the casing corresponding with the elements of a predetermined signal, the corresponding numbers upon the contact plates 31-37 inclusive appear in the said openings 23, and the correctness of the setting of the contact plates may thus be verified prior to the transmission of the signal.

But according to my invention even the selection and placing of the contact plates 31-37 may be accomplished automatically by mechanical means. In Figs. 11 and 12 there is'shown a selector plate which is adapted to be placed upon the top face of the casing 20 in a particular position determined by engagement of the holes 131 therein with pins 24; upon the casing 20. The position of the plate 130 upon the casing 20 is shown by dot-and-dash lines in Fig. 2. The plates 130 have definite structural features, for instance, their upper edges 132 cut to definite contours corresponding with predetermined telephone numbers. The plate 130 illustrated corresponds with the telephone number MI3-3541. T 0 call this number, all of the lugs 30 are pulled down; the plate 130 is laid on the casing 20 below the lugs 30 and pushed upward until the holes 131 engage the pins2et, automatically carrying the lugs 30 to positions determined by the contour of the upper edge 132. Holes 133 may be provided in the plates 130 corresponding with the holes 23 of the casing 20 for verification of the signal before transmitting.

The transmission of the signal is effected by means of electrical impulses induced by breaking the electrical circuit a number of times corresponding to the signal to be transmitted; the breaks being effected in timed groups, each group corresponding with one of the seven elements of the signal. For instance, taking as an example the signal suggested in Fig. 2 by the dot-and-dash line, namely, MI3-3541: the letter M comprising the first element of the signal is in the sixth row, hence the first group will consist of six electrical impulses; the letter I is in the fourth row, hence the second group will consist of four impulses; the thirdelement is 3, hence the third group will consist of three electrical impulses; the same is true of the fourth signal element which is also 3; the

fifth signal element of the number selected is 5, hence five impulses must be transmitted by breaking the circuit five times; the sixth group will consist of four impulses, and the seventh group or signal element of one impulse, completing the signal.

The breaking of the clrcuit to transmit the signalling impulses is effected by means of the contact plates shown in Fig. 3, the under sides of which are shown in Fig. 5. These .plates 31-37 inclusive operate in conjunction with a contact pin 50 so mounted as to pro]ect through a slot 42 in the supporting plate 40 and traverse the contact plates when transmitting the signal. Each of these plates 31-37 has a flat, smooth surface lying in the plane engaged by the contact pin 50, such surface being designated in the drawings by the number 38, so that whenever the pin 50 is in contact with this portion 38 of any of the contact plates 31-37 inclusive, the transmitting circuit is closed, and there is no signalling impulse being transmitted. The contact plates 31-37 are provided with a plurality of grooves 39' separated by ridges 41, the top of each ridge ll being in the same plane as the surface 38. Thus as the contact pin 50 passes transversely over the grooved portion of a plate, the circuit is broken each time the pin passes over one of the grooves 39, and is again closed each time the pin strikes a ridge 41. Each of the plates 31-37 inclusive, is provided preferably with ten grooves 39, arranged as to length in. stepped formation, so that when the contact pin 50 traverses these plates laterally, it breaks the signalling circuit a number of times corresponding with the number of grooves passed over upon the plates, the number of grooves passed over by the traversing contact pin 50 on each plate being determined by the respective lon itudinal positions in which the plates 31-3 have been placed by means of the lugs 30 when setting up the predetermined signal. For instance, when a lug 30 is placed alongside the number 5 on the top face of the casing, the corresponding contact plates 31-37 are placed longitudinally in position to bring five grooves into the path of travel of the contact pin 50.

The mechanism for causing the contact pin 50 to traverse the contact plates is shown particularly in Figs. 6, 9 and 10, and the detail views in connection therewith. The pin 50 is mounted in a grooved roller 51 which travels transversely across the casing upon guides 49 mounted upon brackets 48 and 1nsulated from the base plate 21 preferably through the material of said brackets. The mounting of the pin 50 in the roller 51 is upon a spring 52, to insure contact of the pin 50 at all times with the contact plates 31-37 inclusive, save when passing over grooves 39 thereof, the movement of the pin 50 in the roller 51' being restricted so that it cannot touch the bottom of the grooves. The traversing-movement of the roller 51 upon the guides 49 is effected by means of a pivoted traversing arm provided with a fork 61 which engages a second groove 53 of the roller 51. The forked traversing arm 60 is mounted upon an insulated sleeve 63 fixed to the shaft 62 preferably by means of a square hole therein engaging a squared portion of the shaft 62 as shown in Fig. 8, the forked member 60 being secured to an extended por-' tion of the collar 64 of the sleeve 63 by means of rivets 65 or other suitable means, so that the fork 60 rotates with the pin or shaft 62. The" shaft 62 is rotatably mounted at its lower end in the base plate 21 and at its upper end in a bracket 28 mounted upon the base plate 21. i

A spring 66 is wound about the insulating sleeve 63, and fastened at one end to a pin 67 upon the fork member 60 and at the other end to a pin 29 carried by the casing base plate 21, which spring furnishes the motive power to cause the contact pin 50 to traverse the contact plates 31-37 inclusive, said spring 66 constantly exerting pressure upon thp forked arm 60 to return it to the normal position shown in Fig. 9 whenever it is displaced therefrom.

In order to move the forked traversing arm 60 from the normal position shown in Fig. 9

to the initial position for the automatic transmission of a signal shown in Fig. 10, there is provided a knob 25 projecting upwardly from the top of the casing 20. The knob 25 is fixed by means of a pin 71 to a shaft which is preferably mounted coaxially with the shaft 62, but has no direct connection therewith. The shaft 70 is rotatably mountedin the top of the casing 20, being retained in position by a collar 72, and carries a crank arm 73 having a downwardly extending pin 74 which passes freely through a round hole 75 in a plate 76 rotatably mounted on the shaft 62 between the insulating sleeve 63 and a collar 68 forming part of or attached to the shaft 62. The plate 76 carries beneath it in the same plane as the collar 68 a pawl 80 pivotally mounted as shown in detail in Fig. 8 by means of the screw 81 and provided witha projecting tongue 82 adapted to engage a corresponding notch 69 in the collar 68. The engagement of the tongue 82 of the pawl 80 with the notch 69 of the collar 68 is normally maintained bv means of the spring 83. \Vhen the pawl 80 is in engagement with the collar 68 of the shaft 62, turning theknob 25 counterclockwise results in the force being transmitted through the crank pin 74 to the plate 76 and through the pawl 80 to the shaft 62, thereby moving the forked arm 60 keyed thereto from its normal position as shown in Fig. 9 to its initial position for the transmission of a signal as shown in Fig. 10.

When the parts have been moved to this initial transmitting position, a projecting portion 84 of the pawl 80 strikes against the fixed pin 85, thereby releasing the pawl 80 from its engagement with the shaft 62, and permitting the traversing arm 60 to return under the influence of the spring 66 to the normal position shown in Fig. 9, thereby causing the contact pin 50 to travel transversely along the guides 49 from one side to the other, the pin 50 making contact with the contact plates 31-37 inclusive, and inducing a signalling impulse each time it passes over a groove 39 of said plates.

As shown in detail in Fig. 7, the movement.

of the knob 25 is restricted by means of the pin 91 attached thereto, and the pins 92, 93 attached to the casing 20. The return of the knob to normal position when released is e'ffectcd by means of a spring 94 attached to the casing at 95 and to the knob at 96. The return of the knob 25 to normal position brings with it the arm 73, pin 74, and plate 76, and permits the tongue 82 of the pawl 80 to reengage the notch 69 in the collar 68 of the shaft 62 after the signal transmission has been completed so as to be ready for use again. I I

It is extremely important in the transmission of telephone signals of the character under consideration that each impulse be transmitted in the same predetermined period of time, for instance, one-tenth of a second. In order to meet this timing requirement, I pro vide governing mechanism to control the speed of rotation of the forked arm 60 upon its pivot and insure a uniform rate of rotation; and furthermore, the plates 31-37 inclusive and the respective grooves 39 thereof are made of different widths in order to offset the fact that the pin 50 is traveling at different rates of speed along its straight course, dependent upon its distance from the axis about which the forked arm 60 rotates. Inasmuch as the speed of travel of the pin 50 transversely is greater at the beginning and at the end of its course, the plates 31 and 37 are the widest plates and have the widest grooves 39, the central plate 34 is the narrowest plate, and has the narrowest grooves 39, and the other plates and their grooves are proportioned so that the time taken by the pin 50 to traverse each selected groove 39 of the plates 31-37 inclusive is exactly the same, one-tenth of a second. 5

The governing mechanism may be of any suitable type. I have shown a conventional rotary governor 100 in which frictional pads 101 brush against the cylindrical surface 102 of the casing therefor, the governor 100 being driven at high speed through a multipl ing gear train 103 from a geared sector 104 xed to the shaft 62, the gear wheels of the train 103 being mounted between the base plate 21 and a bracket 27 fixed thereto.

At the left hand side of Figs. 9 and 10 is shown an electrical switch 110 consisting of spring members 111 and 112 normal action of the springs being such as to hold the switch open as shown in Fig. 10. These switch members 111, 112 are carried upon an insulated block. 113 mounted upon thebase plate 21. Alongside this switch is mounted an operating lever 114 pivoted upon the baseplate 21 at 115 and having a preferably insulated pin 116 to contact with the spring member 112 and force it against the spring member 111 to close the switch. The operating lever 114 is arrangedto be engaged by a pin 106 carried by a wheel 105 of the gear train 103, which wheel makes slightly morethan one revolution so that when the pin 106 moves the lever 114 to the position shown in Fig. 9 the switch 110 is closed; whereas when the gear wheel 105 is rotated in a clock-wise direction to the position shown in Fig. 10, the pin 106 again strikes the lever 114, moves it to the position shown in Fig. 10, allowing the switch 110 to open. Excessive movement of the lever 114 is prevented by the pin 118. I

At the right hand side of Figs. 9 and 10 is shown a double switch 120 consisting of three springs 121, 122, 123, each carrying contacts, the normal action of the springs being such as to close the contacts between the springs 121 and 122, and open those between the springs 122 and 123 as shown in Fig. 10; but the first pair of contacts are held open and the sec- 0nd pair closed as shown in Fig. 9 when the forked arm 60 is in normal position, by means of a pin 125, preferably insulated, carried by said forked arm, which may be and preferably is an extension of the pin 67.

When the knob 25 is turned to move the arm 60 from the position shown in Fig. 9, the pin 125 is moved away from the switch 120 and the contacts are allowed to assume the positions shown in Figs. 10 and 13. This opens the receiver circuit switch 122, 123 so that the signalling noise is not heard, and closing the switch 121, 122 short circuits the telephone transmitter. IVhen the arm 60 reaches the position shown in Fig. 10, switch 110 is opened, and the signal transmitting or pulsing circuit normally short circuited thereby is now closed and broken through the pin 50 and the contact plates 31-37 as shown in Fig. 13. \Vhen the arm 60 reaches the position of Fig. 9, the pulsing circuit is short-circuited by the lever 114 closing the switch 110, the transmitter circuit is opened byopening the switch 121, 122, and the receiver circuit is closed by the closing of the switch 122, 123 so that the circuit is ready for the telephone conversation.

The method of operating the device to.

make a call is simple: the lugs 30 are each placed in position corresponding to the elements of the predetermined signal to be transmitted, the telephone receiver is removed from the hook, and the knob '25 is given a half turn to the left, thereby setting and releasing the apparatus for the automatic transmission of the predetermined signal. The further operation of the various parts is entirely automatic, and has been set forth in conjunction with the description thereof.

Having described my invention, I claim: 1. The method of transmitting telephone signals which consists in automatically placing in proper relative positions a set of electrical contacts corresponding to the elements of the predetermined signal to be transmitted, and causing a contacting signal transmitting member to traverse the set of contacts. 2. The method of transmitting telephone signals which consists in selecting electrical contacts corresponding to the elements of the predetermined signal to be transmitted, and

thereupon causing a contacting signal trans- 5. The method of transmitting telephone signals which consists in individually arranglng a series of electrical contacts in relative positions corresponding to the elements of a predetermined signal to be transmitted,

and thereupon causing a contacting signaltransmitting member automatically to pass progressively over all said-contacts.

6. The method-of transmitting telephone signals which consists in placing in proper relative position a set of electrical contacts corresponding to the elements of a predetermined signal to be transmitted, and causing a signal-transmitting member to traverse said contacts in a single continuous movement thereof. y

7. In a telephone signal transmitting apparatus the combination comprising electrical contacts arranged in groups, one group for each signal element, means for selecting a number of contacts from each group corresponding with the elements of the signal to be transmitted, and automatic mechanism for traversing all said contacts to induce signal impulses.

8. In a telephone signal transmitting apparatus, a traversing contact member, and contact plates having circuit breaking grooves therein of varying lengths, whereby the number of grooves traversed by said contact member may be varied by varying the relative positions of said plates with respect to the path of said contact member.

9. In a telephone signal transmitting apparatus, relatively movable selective members for setting the apparatus to transmit a predetermined signal, and a plate having definite structural features to determine the positions of said members for the transmission of the signal predetermined by the structural features of such plate.

10., In an apparatus for the automatic transmission of telephone signals the combination comprising a plurality of groups of contacts slidable in a common plane for setting up the elements of a signal to be transmitted, mechanism for transmitting the signal, and means for dissociating said contacts from the telephone circuit upon completion of the transmission of the signal whereby the contacts maybe set for another call while conversmg.

11. In an apparatus for the automatic transmission of telephone signals the combination comprising a contact traversing member for the transmission of signal impulses, and impulse inducing contact plates each havinga plurality of circuit-breaking grooves therein.

12. In an apparatus for the automatic transmission of telephone signals, the combination comprising a traversing contact member, and contact plates each having therein circuit-breaking grooves of uniformly varying lengths, whereby the number of grooves traversed by said contact member may be varied by varying the relative positions of said plates with respect to the path of said contact member.

In testimony whereof I have signed my name to this specification.

CHARLES S. BATDORF. 

